Patent Document 1 discloses an excreta treatment material, which is a type of water absorption treatment material. The excreta treatment material is provided with a granular core portion and a coating layer portion that covers the granular core portion. The coating layer portion contains an adhesive material and has a function of adhering pieces of the excreta treatment material together, which have absorbed excreta during use. Accordingly, a clump composed of multiple pieces of the excreta treatment material is formed after use.